Engine antidieseling device

ABSTRACT

A container stores a small quantity of air and pumps the air into the idling system of a carburetor when the engine ignition system is turned off. The air reduces the supply of idling fuel to the engine for a time period sufficient to stop engine dieseling. An electrical solenoid valve connected to the engine ignition system controls the injection of the air into the idling passage.

United States Patent Inventors Wilford R. Collingwood Dearborn;

William M. l-lutchison, Allen Park; Frank E. Mangas, Southfield, Mich.

Dec. 12, 1969 May 11, 1971 Ford Motor Company Dearborn, Mich.

Appl. No. Filed Patented Assignee ENGINE ANTIDIESELING DEVICE 7 Claims,2 Drawing Figs.

US. Cl 123/12411, 123/97B, 123/1 19D, 123/198DC Int. Cl F02m 7/06,

F02d 31/00, F02d 13/08 Field of Search 123/198,

198 (DA), 198 (DB), 198 (DC), 97 (B), 119, 124

[56] References Cited UNITED STATES PATENTS 2,817,325 12/1957 Meissner123/198DC 2,943,615 7/1960 Kainz 123/198DC 3,158,144 ll/l964 Walkerl23/198DC 3,354,877 ll/1967 Zub et a]... l23/198DA 3,374,777 3/1968Walker l23/97B 3,398,731 8/1968 Johansson 123/198DC 3,482,557 12/1968 DeLarue et al.. 123/97B 3,482,502 12/1969 Ranft l23/198DC 3,491,737 1/1970 Bumia 123/97B Primary Examiner-Wendell E. Burns Attorneys-John R.Faulkner and Glenn S. Arendsen ABSTRACT: A container stores a smallquantity of air and pumps the air. into the idling system of acarburetor when the engine ignition system is turned off. The airreduces the supply of idling fuel to the engine for a time periodsufficient to stop engine dieseling. An electrical solenoid valveconnected to the engine ignition system controls the injection of theair into the idling passage.

ENGINE ANTIDIESELING DEVICE SUMMARY OF THE INVENTION The large amount ofemission control equipment required on modern day internal combustionengines has resulted in a condition known commonly as dieseling in whichthe engine continues to run after the ignition switch has been turnedoff.

Dieseling typically results from the ignition of the f uel-air mixingdieseling under most engine operating conditions, it is ineffective whenthe fast idle cam of the engine is being used to position the throttleblade during engine warmup. Dieseling in fact is probably most acutewhen the fast idle cam is in effect since just a few cycles of engineoperation can heat small deposits in the engine combustion chamber toincandescence and the rich mixture supplied to the combustion chamber bythe partially closed choke and the open throttle blade can be ignitedreadily by the deposits.

This invention provides a system for preventing positively enginedieseling under all conditions of engine operation. In an internalcombustion engine having a source of electrical energy, an inductionpassage for supplying fuel and air to a combustion chamber, a movablethrottle blade in the induction passage and an idling passage forsupplying idling fuel to the induction passage downstream of thethrottle blade, the system of this invention comprises a mechanism thatincludes a small container for storing a relatively small quantity ofair. A conduit connects the container with the idling passage and avalve located in the conduit permits communication between the containerand the idling passage when the ignition system is turned off. Air fromthe container then flows into the idling passage to reduce the supply ofidling fuel and stop engine operation.

In an advanced embodiment of this invention, the container includes adiaphragm that has one side exposed to the intake manifold vacuum of theengine and the other side communicating with the valve and via the valvewith the conduit. The valve is made up of a valve rod movable onto alower seat formed at the entrance to the conduit and an upper seat thatcommunicates with the atmosphere. A spring normally urges the valve rodonto its upper seat but an electrical solenoid actuated with the engineignition system overcomes the force of the spring to move the valve rodonto the lower seat.

When the ignition system is turned on and the engine has been started,manifold vacuum applied to the bottom of the diaphragm in the containerurges the diaphragm to a lowered position. Actuation of the ignitionsystem moves the valve rod to its lower position so the downwardmovement of the diaphragm draws air past the upper valve seat and intothe chamber. The components stay in this position throughout normalengine operation; since the valve rod is closing the conduit, the systemdoes not interfere with engine operation. When the ignition switch isturned off to shut down the engine, deactivation of the solenoid permitsmovement of the valve rod to its upper seat, thereby connecting thecontainer with the engine idling passage. At the same time the risingmanifold pressure permits a spring to move the diaphragm of thecontainer to an upward position, thereby forcing air through the conduitand into the carburetor idling passage where the air cuts off fuel flowto stop any engine dieseling.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a schematic view of aninstallation of the system of this invention showing the relationship ofthe container to the engine ignition system and the carburetor duringnormal engine operation.

FIG. 2 is a sectional view of the container and the valve assemblyshowing the relationship of the components when the engine is shutoff.

DETAILED DESCRIPTION Referring to the drawing, a carburetor for aninternal combustion engine has an induction passage 12 for supplyingfuel and air to a combustion chamber of the engine. A throttle blade I4is mounted pivotally in induction passage 12 tocontrol the flow of fueland air through the induction passage. Upstream of throttle blade 14 isa venturi section I6 that produces an appropriate main fuel meteringsignal. Downstream of throttle blade 14, induction passage I2communicates with the engine intake manifold passage I8 thatcommunicates with the engine combustion chamber.

A fuel reservoir is located in carburetor I0 alongside induction passageI2. Reservoir 20 communicates with a fuel well 22 that supplies fuel toan idling passage 24 through a metering jet 26. Idling passage 24communicates through a port 28 with induction passage I2 downstream ofthrottle blade 14.

Mounted near carburetor '10 is a small air container 30 that has amovable diaphragm 32 mounted therein to divide the container into anupper chamber 34 and a lower chamber 36. A compression spring 37 islocated in lower chamber 36 where it urges diaphragm 32 toward an upperposition shown in FIG. 2. The bottom of the container includes a ferrule38 and a hose 39 mounted on the ferrule connects lower chamber 36 withinduction passage 12 at all times at a point downstream of throttleblade 14. A guide rod 40 attached to the diaphragm slides in ferrule 38to maintain proper alignment of the diaphragm.

A cap 41 mounted on top of container 30 has a small space 42 definedpartially by a lower plate 43 that fits on top of chamber 34. Space 42communicates with chamber 34 through a short passage 44 in plate 43.Plate 43 also contains a valve seat 46 at the opening into space 42 of apassage 48. Another valve seat 50 is located in the upper part of cap 41in alignment with valve seat 46. Valve seat 50 is the opening into space42 of a passage 52 that communicates with a port 58 at the upper part ofinduction passage 12. A movable valve rod 54 is positioned to seat oneither of the upper and lower valve seats. Rod 54 is urged onto seat 50by a spring 56. The valve rod is made of a material that is movable by amagnetic'field. Passage 48 communicates with a passage 60 formed in thecarburetor that in turn communicates with idling passage 24.

Positioned around the outside of the upper part of cap 41 is a solenoidcoil 62. Coil 62 is connected electrically to the vehicle ignitionsystem indicated by numeral 64 which is connected to an ignition switch66 and the vehicle battery 68. Switch 66 is actuated manually by thevehicle driver and is closed when the engine is operating. Solenoid coil62 thus is energized when the engine is operating; when energized thecoil applies a magnetic field to valve rod 54 that moves the valve rodonto lower seat 46. When the valve rod is in this lowered position,upper chamber 34 communicates with the atmosphere via passage 44, space42, valve seat 50, passage 52 and port 58.

The system of this invention .operates in the following manner. When thevehicle operator starts the engine, the solenoid moves valve rod 54 asdescribed above to connect upper chamber 34 with the atmosphere. Thereduced intake manifold pressure in the intake manifold passage I8 drawsdiaphragm 32 into a lowered position as shown in FIG. 1, thereby fillingthe upper chamber 34 with a small quantity of air. During continuedengine operation, variations in manifold pressure can move diaphragm 32slightly, but this movement has no effect on engine operation since theair simply moves back and forth through port 58.

When the operator opens switch 66 to shut down the engine, solenoid 62is deactivated and spring 56 pushes valve rod onto upper seat 50 (SeeFIG. 2). Opening switch I66 also deactivates the engine ignition system64, which produces an increase in the manifold pressure in intakemanifold 18. The increase in pressure permits spring 37 to movediaphragm 32 upward into chamber 34 and the air in chamber 34 is forcedthrough passage 48 into the idling passage 24 of the carburetor where itreduces fuel flow through jet 26 and thereby reduces the composition ofthe fuel air mixture reaching the engine combustion chambers to thepoint where the mixture no longer is combustible. The engine thus ceasesoperation without dieseling,

The amount of air necessary to prevent dieseling varies somewhat withengine size and carburetor characteristics and must be determinedempirically. A minimum of about I cubic inch of air is needed to preventdieseling under most anticipated conditions. If desired, a check valvecan be included in passage 52 and valve rod 54 then moves onto only oneseat controlling airflow into the idling passage.

Thus this invention provides a positively acting system for preventingengine dieseling regardless of the positions of the carburetor chokeplate or throttle blade. The system can be incorporated in vehicleproduction or added to vehicles out in the field by relatively simpleoperations.

We claim:

1. In an internal combustion engine having a source ofelcctrical energy,an induction passage for supplying fuel and air to a combustion chamber,an ignition system connected to said source of electrical energy forsupplying an ignition spark to said combustion chamber, a movablethrottle blade mounted in said induction passage, and an idling passagefor supplying idling fuel to said induction passage downstream of saidthrottle blade, a mechanism for preventing engine dieseling comprising:

container means for storing a quantity of air,

a conduit connecting said container means with said idling passage, and

means for transmitting air from said container means via said conduit tosaid idling passage when said ignition system is turned off. said airreducing the supply of idling fuel via said idling passage to saidcombustion chamber to stop engine operation.

2. The engine of claim 1 in which the transmitting means comprises avalve located in said conduit for controlling airflow through saidconduit, said valve comprising an electric solenoid connectedelectrically to said ignition system and a valve rod movable by themagnetic field produced by energization of said solenoid. said solenoidclosing said valve to prevent airflow through said conduit when theignition system in turned on and opening said valve when the ignitionsystem is turned off.

3. The engine of claim 2 in which the container means comprises amovable diaphragm dividing said container into first and secondchambers, said first chamber communicating with said conduit throughsaid valve, and a spring urging said diaphragm into said first chamber.

4. The engine of claim 3 in which the second chamber communicates withthe intake manifold of the engine so the intake manifold vacuum drawssaid diaphragm out of said first chamber.

5. The engine of claim 4 comprising a valve seat for each end of saidvalve rod, the first valve seat connecting said first chamber to saidconduit and the second valve seat connecting said first chamber to theatmosphere, and a spring urging the valve rod to said second seat, saidsolenoid moving the valve rod to the first seat when energized.

6. The engine of claim 1 in which the container means comprises amovable diaphragm dividing said container into first and secondchambers, said first chamber communicating with said conduit throughsaid valve, and a spring urging said diaphragm into said first chamber.

7. The engine of claim 2 comprising a valve seat for each end of saidvalve rod, the first valve seat connecting said first chamber to saidconduit and the second valve seat connecting said first chamber to theatmosphere, and a spring urging the valve rod to said second seat, saidsolenoid moving the valve rod to the first seat when energized. 4

1. In an internal combustion engine having a source of electricalenergy, an induction passage for supplying fuel and air to a combustionchamber, an ignition system connected to said source of electricalenergy for supplying an ignition spark to said combustion chamber, amovable throttle blade mounted in said induction passage, and an idlingpassage for supplying idling fuel to said induction passage downstreamof said throttle blade, a mechanism for preventing engine dieselingcomprising: container means for storing a quantity of air, a conduitconnecting said container means with said idling passage, and means fortransmitting air from said container means via said conduit to saididling passage when said ignition system is turned off, said airreducing the supply of idling fuel via said idling passage to saidcombustion chamber to stop engine operation.
 2. The engine of claim 1 inwhich the transmitting means comprises a valve located in said conduitfor controlling airflow through said conduit, said valve comprising anelectric solenoid connected electrically to said ignition system and avalve rod movable by the magnetic field produced by energization of saidsolenoid, said solenoid closing said valve to prevent airflow throughsaid conduit when the ignition system in tuRned on and opening saidvalve when the ignition system is turned off.
 3. The engine of claim 2in which the container means comprises a movable diaphragm dividing saidcontainer into first and second chambers, said first chambercommunicating with said conduit through said valve, and a spring urgingsaid diaphragm into said first chamber.
 4. The engine of claim 3 inwhich the second chamber communicates with the intake manifold of theengine so the intake manifold vacuum draws said diaphragm out of saidfirst chamber.
 5. The engine of claim 4 comprising a valve seat for eachend of said valve rod, the first valve seat connecting said firstchamber to said conduit and the second valve seat connecting said firstchamber to the atmosphere, and a spring urging the valve rod to saidsecond seat, said solenoid moving the valve rod to the first seat whenenergized.
 6. The engine of claim 1 in which the container meanscomprises a movable diaphragm dividing said container into first andsecond chambers, said first chamber communicating with said conduitthrough said valve, and a spring urging said diaphragm into said firstchamber.
 7. The engine of claim 2 comprising a valve seat for each endof said valve rod, the first valve seat connecting said first chamber tosaid conduit and the second valve seat connecting said first chamber tothe atmosphere, and a spring urging the valve rod to said second seat,said solenoid moving the valve rod to the first seat when energized.